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. Author manuscript; available in PMC: 2025 Mar 1.
Published in final edited form as: Osteoarthritis Cartilage. 2023 Sep 19;32(3):329–337. doi: 10.1016/j.joca.2023.09.007

Table 3.

Test set results for clinical and proteomic variables as OA diagnostics.

DISCOVERY ANALYSES (TRAINING SET) VALIDATION ANALYSES (TESTING SET) SENSITIVITY ANALYSES FNIH WOMAC pain=0 subset SENSITIVITY ANALYSES FNIH WOMAC pain >0 subset
Model TRAINING SET ROC-AUCs (95% CIs) TRAINING SET PR-AUCs (95% CIs) TESTING SET ROC-AUCs (95% CIs) TESTING SET PR-AUCs (95% CIs) TESTING SET ROC-AUCs (95% CIs) TESTING SET PR-AUCs (95% CIs) TESTING SET ROC-AUCs (95% CIs) TESTING SET PR-AUCs (95% CIs)
BMI 0.657 (0.588, 0.721) 0.886 (0.848, 0.926) 0.570 (0.473, 0.665) 0.812 (0.747, 0.882) 0.460 (0.348, 0.58) 0.547 (0.442, 0.678) 0.629 (0.524, 0.73) 0.767 (0.680, 0.864)
BMI, age, sex 0.689 (0.62, 0.753) 0.893 (0.856, 0.932) 0.593 (0.497, 0.687) 0.823 (0.757, 0.893) 0.515 (0.405, 0.629) 0.582 (0.472, 0.725) 0.636 (0.533, 0.732) 0.773 (0.687, 0.868)
ACTG 0.757 (0.697, 0.811) 0.934 (0.906, 0.956) 0.705 (0.612, 0.788) 0.897 (0.844, 0.941) 0.697 (0.591, 0.793) 0.750 (0.633, 0.855) 0.709 (0.617, 0.798) 0.854 (0.780, 0.917)
ACTG + BMI 0.776 (0.719, 0.825) 0.942 (0.92, 0.96) 0.703 (0.608, 0.787) 0.884 (0.828, 0.936) 0.650 (0.537, 0.754) 0.688 (0.563, 0.813) 0.733 (0.635, 0.822) 0.848 (0.766, 0.919)
23 RF peptides 0.929 (0.9, 0.955) 0.984 (0.977, 0.991) 0.848 (0.766, 0.916) 0.936 (0.884, 0.979) 0.837 (0.751, 0.913) 0.834 (0.717, 0.938) 0.854 (0.771, 0.922) 0.908 (0.833, 0.968)
23 RF peptides + BMI 0.938 (0.913, 0.961) 0.987 (0.98, 0.992) 0.853 (0.767, 0.923) 0.929 (0.874, 0.979) 0.832 (0.743, 0.913) 0.809 (0.694, 0.932) 0.864 (0.778, 0.932) 0.903 (0.825, 0.972)
17 uncorrelated peptides 0.919 (0.884, 0.949) 0.981 (0.97, 0.99) 0.841 (0.757, 0.913) 0.932 (0.878, 0.976) 0.834 (0.744, 0.913) 0.826 (0.708, 0.937) 0.846 (0.761, 0.918) 0.901 (0.823, 0.965)
17 uncorrelated peptides + BMI 0.925 (0.89, 0.953) 0.982 (0.972, 0.99) 0.845 (0.758, 0.918) 0.926 (0.871, 0.976) 0.829 (0.74, 0.911) 0.807 (0.691, 0.93) 0.854 (0.766, 0.927) 0.897 (0.818, 0.968)
8 significant peptides 0.907 (0.871, 0.938) 0.978 (0.967, 0.987) 0.833 (0.751, 0.905) 0.929 (0.876, 0.973) 0.830 (0.738, 0.911) 0.819 (0.700, 0.933) 0.835 (0.749, 0.907) 0.898 (0.819, 0.962)
8 significant peptides + BMI 0.916 (0.881, 0.945) 0.981 (0.971, 0.989) 0.842 (0.758, 0.914) 0.925 (0.87, 0.975) 0.824 (0.732, 0.906) 0.802 (0.686, 0.927) 0.853 (0.765, 0.925) 0.897 (0.818, 0.968)

23 peptides and BMI were selected based on random forest (RF)>0.9; 17 uncorrelated peptides were selected based on RF=1, WMW p value and uncorrelated status; 8 significant peptides were selected based on RF=1, WMW p value, uncorrelated status, and association with OA status in multivariable logistic regression; for the list of these sets of peptides see Table 2. 231 (39%) FNIH cases had baseline WOMAC pain scores=0